JPS626951B2 - - Google Patents

Description

Detailed Description of the Invention The present invention relates to a method for machining an inner ring of a double-row tapered roller bearing or a double-row tapered roller bearing used in back-to-back configurations, and particularly relates to a method for machining the inner ring of a double-row tapered roller bearing or a tapered roller bearing used in a double-row arrangement such as back-to-back configuration. The present invention relates to a method of machining an inner ring of a tapered roller bearing that can always maintain a constant difference in the inner ring of a tapered roller bearing.

In general, for double-row tapered roller bearings or tapered roller bearings used in double rows such as back-to-back, the transfer surface groove and collar surface are machined with finishing dimensions based on the small-diameter end face of the inner ring, and then If the assembled height (plane difference) from the small diameter end face of the inner ring to the small diameter end face (in the case of double row tapered roller bearings, the dimension from the center of the outer ring width to the small diameter end face of the inner ring) can be maintained constant, the clearance tolerance can be strictly controlled, and the As shown in Figure 1, it can be assembled without a spacer. Note that 1 is a bearing outer ring, 2 and 2' are bearing inner rings, and 3 and 3' are tapered rollers.

However, the machining of the inner rings 2 and 2' of this type of bearing is
Due to the adsorption force of the magnetic chuck and the cutting direction of the grindstone, machining must be performed using the large diameter end face as a reference, and dimensions such as the transfer surface groove diameter during assembly are affected by variations in the inner ring width dimension, so the gap tolerance must be adjusted. It was difficult to strictly manage it.

That is, conventionally, as shown in FIG. 2, the large diameter end face of the inner ring 2 is held by suction on a packing plate 4 of a grinding machine, and a measuring device 5 is installed at a position a predetermined distance c away from the packing plate 4. While measuring the groove diameter of the raceway surface, the packing plate 4 and inner ring 2 were rotated and ground using a grindstone 6. this is,
Since the raceway groove diameter is measured at a certain position c from the large-diameter end face of the inner ring 2, the raceway groove 2a is machined based on the large-diameter end face, and the raceway groove 2a is machined based on the large-diameter end face. Due to variations in the width dimension of the inner ring 2, the measurement position of the raceway groove 2a differs for each workpiece, resulting in different measurement dimensions.

Conventionally, during assembly, as shown in FIG. 3, a spacer 7 was interposed between the small diameter end faces of the inner rings 2 and 2' to absorb the dimensional error. Furthermore, as shown in FIG. 4, when two tapered roller bearings 8, 8' are assembled back-to-back, they are assembled with spacers 9, 9' interposed. However, in this case, a large number of spacers with different dimensions must be prepared in advance, and an appropriate spacer must be selected in accordance with the width dimension of the inner ring each time the assembly is performed.
Workability and compatibility were very poor.

Therefore, the present applicant has proposed a machining method in which raceway grooves are first machined while performing in-process control based on the width dimension of the inner ring and using the small diameter end face side as a reference. As shown in Fig. 5, a first measuring device 12 for measuring the width dimension is installed at one end of an L-shaped fixed block 11 disposed on the grinding machine body 10, and a first measuring device 12 for measuring the raceway groove diameter is installed at the other end. Attach a second measuring device 13 to the measurement device 13, and apply a value k obtained by multiplying the deviation Z− _Z0 of the dimension Z measured by the first measuring device 12 from the reference width dimension _Z0 by a predetermined coefficient k to the second measuring device 13. Feedback (zero point calibration)
The rolling surface grooves are ground by in-process control using a measuring device 13. However, with the above processing method, although it is possible to perform processing based on the small-diameter end face, it is affected by the finishing accuracy of the width grinding process using a double-headed surface grinder, which is the preceding process, and the diameter of the groove on the raceway surface cannot be adjusted. Accurate in-process control was difficult.

That is, in general, this type of width grinding has relatively poor finishing accuracy in terms of the finished dimension itself and the perpendicularity of the width surface to the axis, compared to other processes. If you try to provide feedback (zero point calibration) to the second measuring device 13 based on such a width dimension with low accuracy, the amount of feedback will inevitably increase, making the calibration itself very difficult. The contact surface between the outer peripheral surface of the inner ring (workpiece) and the shoe that supports the workpiece of the grinding machine changes each time, and the amount of offset between the center of rotation of the packing plate 14 and the center of the inner ring 2 changes, causing rolling. This had a negative effect on the measurement accuracy and roundness of the face groove dimensions. In addition, when assembling this type of bearing without a spacer, as shown in Figure 6, it is not only necessary to control the transfer surface groove diameter dimension R based on the small diameter end face, but also to directly control the dimension K from the small diameter end face to the collar face. , the influencing tolerance (±ΔA) must also be strictly controlled, and it has been impossible to control this (±ΔA) with the above-mentioned processing method.

In view of the above-mentioned conventional problems, this invention improves and eliminates them by grinding the width surface after grinding the transfer surface, and the standard value (target dimension) of the inner ring transfer surface groove diameter dimension machined by the normal grinding method. ) is converted into a deviation in the axial direction of the inner ring, and the zero point of the in-process control gauge for small-diameter end face machining is shifted by this converted value. Next, while performing in-process control using the gauge, the small-diameter end face and flange of the inner ring are ground using a small-diameter end-face grinding wheel and a flange grinding wheel separated from the grindstone by a certain distance.

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 7, 20 is an inner ring of a tapered roller bearing that is held by suction on a packing plate (not shown) of a grinding machine, 22 is a flange grinding wheel for grinding the flange 21 of the inner ring 20, and 23 is a flange grinding wheel. rotary dress, 2
4 is an end face grinding wheel for grinding the small diameter end face 20a of the inner ring 20, and 25 is a rotary dress for the end face grinding wheel. The flange grinding wheel 22 and the end face grinding wheel 24
is a constant diameter dimension relationship, and the grinding wheel spindle 2
6 are arranged concentrically with a grindstone spacer 27 interposed between them, and fixed with a flange nut 28, and the large flange surface 21 of the inner ring 20 is connected to the outer peripheral surfaces 22a and 24a, respectively.
a and the small diameter end face 20a are ground. 29 is a grindstone flange. In addition, the outer peripheral surface 22 of the tsuba grinding wheel 22
a has a constant angle α with the axis of the grindstone spindle 26. Rotary dress 23 for tsuba grinding wheel
adjusts the angle of the tip surface 23a and is fixed to a dress correction slide (not shown). and has a dress correction slide (not shown). 30 is mounted on a fixed block (not shown) of the grinding machine, and the inner ring 20
A first measuring device 31 measures the dimension (width dimension) from the end surface of the packing plate to the small diameter end surface 20a of the inner ring 20 by bringing it into contact with the small diameter end surface 20a of the inner ring 20 at a certain distance from the end surface of the packing plate.
This is a second measuring device that measures the raceway groove diameter of the.

In the above configuration, the machining method is explained as follows: A bearing whose rolling surface grooves are ground to a target dimension based on the large-diameter end face, regardless of the width dimension of the workpiece, using a normal grinding method in the previous process. The large-diameter end surface side of the inner ring 20 is attracted to the packing plate, and the first measuring device 30 is attached to the small-diameter end surface 20a of the inner ring 20.
The measuring instruments 31 of the inner ring 2 are brought into contact with the raceway grooves, respectively.
Measure the width dimension and raceway groove diameter of 0. At this time, the deviation (processing error) between the raceway groove diameter measured by the second measuring device 31 and the reference raceway groove diameter (design target groove diameter) is determined. The deviation value is converted into a deviation value in the inner ring axial direction and fed back to the first measuring device 30, and then, until the measured value of this zero point calibrated second measuring device 31 reaches a predetermined inner ring width dimension, 1 with constant diameter dimension relationship
Tsuba grinding whetstone 22 and end face grinding whetstone 24
The large flange surface 21a and the small diameter end surface 20a of the flange 21 of the inner ring 20 are simultaneously ground.

The raceway groove diameter of the inner ring 20 ground in this way is set corresponding to the inner ring width dimension.
The assembly height of the raceway groove is kept constant based on the small diameter end face 20a, and there is no spacer when assembling back to back.
Alternatively, it can be assembled with one type of spacer, improving work efficiency.

More specifically, the processing method of the present invention, as shown in FIG.
are simultaneously machined using an in-process control gauge whose zero point is calibrated according to the groove finishing dimensions. At this time, the end face grinding wheel 24 and the flange grinding wheel 22 are integrated with a constant diameter dimension relationship (separation distance is constant). Therefore, the dimension K between the small diameter end surface 20a and the large flange surface 21a of the ground inner ring 20 is always kept constant. Therefore, now suppose that the transfer surface groove diameter of the inner ring 20 has been finished larger by △R than the standard transfer surface groove diameter R, and the inner ring 20 with the width dimension If it is necessary to grind △D from the end face 20a, this △D
is expressed by the following formula. Note that the angle between the transfer surface groove and the horizontal plane is defined as β. Also, the standard width dimension is Xo.

△D/△R=cotβ ∴△D=△Rcotβ …(1) Therefore, if the width dimension measured by the first measuring device 30 is ground until it becomes Xo + △Rcotβ, the transfer surface based on the small diameter surface The groove diameter becomes R, and at the same time, the dimension from the small diameter end face 20a to the large flange face 21a is finished to the standard dimension K. Therefore, the assembly height can be kept constant without being affected by the width dimension including processing errors.

As explained above, the present invention is a method for machining an inner ring of a tapered roller bearing, in which the inner ring transfer surface is ground and finished, and then the inner ring small diameter end face is ground and finished. This converted value is converted into a deviation in the direction, and this converted value is fed back to the in-process control gauge for small-diameter end face machining, and this gauge allows end face grinding of the small-diameter end face of the inner ring and the collar, which are mounted integrally with a certain distance apart. Since the grinding wheel and the flange grinding wheel are used to simultaneously grind, even if there are variations in the raceway groove diameter and width dimensions, the raceway groove dimensions can be determined based on the small diameter end face without being affected by them. The assembly height with respect to the raceway surface of the outer ring is constant, and the assembly height does not need to be adjusted when assembling a double-row tapered roller bearing or when assembling a double-row back-to-back assembly. The bearing can be assembled without a spacer or with only one type of spacer, improving work efficiency when assembling the bearing. In addition, in the present invention, the finished width dimension is subjected to feedback control based on the variation in the diameter dimension of the transfer surface groove with excellent finishing accuracy, so the amount of feedback can be reduced and control can be performed easily and accurately. . Furthermore, in the present invention, the dimension from the small diameter end face to the flange is always kept constant during grinding, so the width dimension is determined by the axial length corresponding to the deviation of the measured raceway groove diameter dimension from the reference value. By simply adding it to the reference value (design target dimension), the dimension from the small diameter end face to the flange can be finished to the specified dimension (a value that takes into account the variation in the transfer surface groove diameter dimension). When the bearing is assembled, the bearing clearance (bearing preload) can also be set strictly.

[Brief explanation of the drawing]

Figure 1 is a sectional view of the main parts of a double-row tapered roller bearing assembled without a spacer, Figure 2 is a schematic diagram showing a conventional method for machining the inner ring of the bearing, and Figure 3 is a typical double-row tapered roller bearing. A sectional view of the main part showing the
Figure 5 is a schematic diagram showing the conventional machining method based on the small diameter end face, and Figure 6 is an enlarged view showing the problems with the conventional machining method. FIG. 7 is a schematic diagram showing a specific example of the inner ring machining method according to the present invention, and FIG. 8 is an explanatory diagram showing the machining principle. 20... Bearing inner ring, 21... Tsuba, 22... Tsuba grinding wheel, 23... End face grinding wheel.

Claims (1)

[Claims] 1 A method for processing the inner ring of a tapered roller bearing, in which the inner ring small diameter end face is finished by grinding after the inner ring transfer surface is ground and finished, and the deviation of the transfer surface finish dimension from the target finished dimension is converted to the deviation in the inner ring axial direction. The converted value is fed back to the in-process control gauge for small-diameter end face machining, and this gauge allows the small-diameter end face of the inner ring and the flange to be simultaneously processed by the end face grinding wheel and the flange grinding wheel, which are installed integrally with a certain distance apart. A method for machining an inner ring of a tapered roller bearing, characterized by performing grinding.